Consolidating power supply sections for multi-FX?

[tatou]

I'm working on a 2-in-1 pedal design that combines a modded Gainster-like overdrive with a modded Rat-like distortion.

If possible, I'd like to simplify/reduce the parts count by consolidating the two power sections. They are essentially the same, but with a few value changes (+1 resistor):



Since I'm still a relative n00b, I'm not sure what effect changing these values would have on either circuit. So I ask:

1. How would you recommend consolidating these two into a shared power section, and

2. Why? (That is, what effect are the final/chosen values expected to have on each sub-circuit?)

Thanks!!

[PRR]

https://s22.postimg.org/rzqvabq81/tatou-1.gif

[tatou]

Thanks!

Can someone explain a bit about the function of these components? Here's the suggested circuit from @PRR:



Here are my specific questions:

• R21+R22 split the power voltage from 9V to 4.5V. Is there some reason to us 10k, or does the value particularly matter?
• C22 is, I think, a filter cap to reduce AC hum from the power supply. What about C21?
• The 47R resistor seems like it has little to no effect, what purpose does is serve?

Thanks!

[duck_arse]

the 47R works against C22 (and C20), providing an R//C filter for EVERYTHING connecting to "VC". R21//R22 allow a larger current flow as 10k's than as 100k's, and so the V/2 they produce is harder to "shift" with your loads. and then C21 provides a low impedance route to ground for EVERYTHING connecting to "VB", much less than the R21 does. this means less noise on your referenced inputs.